1. Field of the Invention
The present invention relates to a moving picture and audio data reproducing method for reproducing moving picture and audio data from compressed moving picture and audio data suitable for multimedia communication and a system therefor.
2. The Prior Art
As communication technologies and the processing speed of machines and instruments such as computers processing communication data have been improved, and also, these machines and instruments have been popularized, multimedia communication including picture data along with conventional text and audio data have been widely used. In such multimedia communication, since the amount of data to be processed is large, the process time for communicating data largely depends on the efficiency of the reproduction process performed by communication terminal units.
In a first related art reference (Japanese Patent Laid-Open Publication No. 7-115630), the time period for sending data that represent performance specifications to be exchanged between a local terminal unit and a remote terminal unit through a communication line is reduced. In other words, unlike the conventional system of which the all performance specifications of the local terminal unit are communicated in the negotiation stage, this related art reference discloses that only the ability specifications corresponding to predetermined communication mode are sent to the remote terminal unit so as to reduce the time period for which the performance specifications is sent. In addition, with a recognizing circuit that recognizes the remote terminal unit and a storing circuit that stores the performance specifications of the remote terminal, in later negotiations, the performance specifications stored in the storing circuit are used, whereby the time period thereof is reduced.
A second related art reference (Japanese Patent Laid-Open Publication No. 4-180489) discloses a technology for displaying a picture on a monitor display of a TV phone. In this technology, due to the fact that pictures are not frequently changed in the communication start phase, a plurality of desired picture signals are sent and stored in a memory beforehand. Thus, when pictures are displayed, only address information of the memory is sent. Thus, the picture transmission time can be apparently reduced.
A third related art reference (Japanese Patent Laid-Open Publication No. 63-288556) discloses a picture communication method for sending and receiving picture information with a telephone line. In this method, after a server has sent a transmission start signal composed of a predetermined DTMF signal to a terminal for a predetermined time period corresponding to a transmission request operation of the sending side, the server starts sending picture information with a high speed modem. Only when the terminal has received the transmission start signal for the predetermined time period or longer, it starts receiving the picture information with the high-speed modem. Thus, in comparison with the conventional facsimile communication and so forth, the transmission procedure is remarkably simplified. In particular, when the amount of picture information is small, the communication can be effectively performed.
However, in the conventional technologies for reproducing picture data, when the current picture being reproduced is skipped to a desired picture, it takes a time. In other words, the reproducing process cannot be smoothly performed. This is because there are control portions in the terminal that reproduces moving picture data and also in the server that sends the compressed moving picture data. And it takes a time for these control portions to communicate each other by commands according to predetermined protocol.